(1) Field of the Invention
The present invention relates to a ceiling runner attachment system in which an attachment clip is provided that is engageable with either air distribution bars or inverted-T runners thereby providing attachment means for ceiling runners positioned either parallel the supporting structure or perpendicular to the supporting structure.
(2) Description of the Prior Art
It is desirable to provide an interface connection between panel engaging ceiling runners and ceiling support structures that will provide acoustical and structural integrity. It is particularly desirable for such connections to be adaptable when wall panels, or partitions, are installed parallel or transverse to air distribution bars or, parallel or transverse to conventional T grids. Similarly, in combination support structure systems where air distribution bars comprise a portion of the ceiling structure and conventional inverted-T runners comprise the remaining portions of the ceiling structures, it is also desirable to provide attachment means adaptable to such combination wherein wall panels, or partitions, may be positioned parallel or transverse to said supporting ceiling structures.
Attachment runner systems have been constructed in the past. One such attempt is shown in U.S. Pat. No. 3,003,735, to Havener, which provides an attachment clip for attachment to ceiling T grids above and attachment to partition ceiling runners along the underneath side of the clip. Problems still remain unsolved. While this clip is designed to provide attachment to ceiling T grids without defacing the exposed grid flange with screw holes or the like, the rotating snap-on engagement severely scratches the grid flange none the less. Bolting is required to secure partition ceiling runners to the clip and a gap is left between the ceiling runner and T grid as a result of the combined thickness of the clip and fastener means. Moreover, an additional problem is confronted in that partition ceiling runners installed perpendicular to the ceiling T grid provide less lateral resistance to loads than those installed parallel the ceiling T grid because the clip has a tendency to slide in that direction. Lastly, in combination grid systems wherein the supporting structures comprise both air distribution bars and inverted-T runners, a different attachment clip would be required for engagement with engageable flanges located on conventional air distribution bars.
In another ceiling runner attachment system a steel bar portion is twist-engaged to a ceiling grid. A second member, being a metal pan with legs extending upwardly, is snapped-on to engage the bar member and provide a space between the pan and the bar for the insertion of acoustical material. A partition ceiling runner is then fastened, by screws or the like, to the underside of the pan member. This clip structure is adaptable to use with air distribution bars, as well as conventional T grid systems, since a gap is provided between the pan and bar members to permit air flow therethrough. However, certain disadvantages entail the use of this attachment system. The pan member provides an unsightly appearance from below. Again, as with previous systems, the twist-engaging attachment of the bar members scratches and mars the ceiling grid system support members. The pan member, being of sheet metal construction, lacks rigidity and is susceptible to flexing. Finally, with transverse partition alignments, sufficient resistance to lateral loading cannot be accomplished unless the bar member is fastened by screws or the like to the ceiling grid after the initial twist engagement.
Other attachment systems have been utilized for ceiling runner attachment systems. No systems in the part have been able to overcome the obstacles created in trying to obtain an acoustical ceiling having a recessed ceiling system that provides a shadow line effect wherein no marring of the grid support member occurs during installation and wherein exposed flanges of support structures remain free from screw holes, or the like, for fastening means. In addition to these basic problems, unsolved in the past, a further problem, that stood unsolved, was the inability of previous systems to provide an attachment system that would accommodate a ceiling support structure comprising both air distribution bars and conventional inverted-T runners wherein demountable partition assemblies were desired that kept the exposed portions of ceiling structures undamaged during installation and after removal. Along with the foregoing, an obstacle is presnted in attempting to solve the attachment difficulties without restricting air flow in systems incorporating air distribution bars. It has furthermore been desirable for such a system to also provide a means for ceiling runners, engaged to wall panels or partitions, to be located either parallel or perpendicular to such ceiling structure support members. Prior structures have not solved these numerous attendant problems which arise in attempting to provide this long desired ceiling runner attachment system. The new and useful ceiling runner attachment system of this invention overcomes all of the deficiencies associated with prior systems.